Rotatable hone



H. R. BLLETER ROTATABLE Home 5 Sheets-Sheet l Filed March 5. 1949 U Iv. .m mr @m NMAJ@ A i ww @www @w QGQQ.

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H. R. BILLETER ROTATABLE HONE May. 12, 1953 Filed March 3. 1949 3 Sheets-Sheet 2 s sheets-sheet s H. R. BILLETER ROTATABLE HONE ,N .NN NN M s www@ IN V EN TOR.

lll [l May' 12, 1953 Filed March 3. 1949 Patented May 12, 1953 UNHED lSTATES PATENT OFF-ICB;

2,637,954l noTA'rABLE HoNE Henry Robertvilleter, Highland Park, Ill., as- -wsgnor to Ammcov-Tools, Inc., North Chicago, Illy., a corporation of Illinois 1 Application Mar-ch 3, 1949, seria; No. 1,6 claims. (citi- 184m bers'l are employed(v In tools'heretofore` devised;

the'sizerequirements of the tool., when verysmall cylinders or faces'are to beV honed, 'have limited the tool to a single' abradingv member withv resultant loss in ef'ciency Also, such size requirements have heretoiore prohibited the useof a tool'having pluralabradi-ng members in that expansion adjustment would be so limited as not to be practicable.` One of the objects of my inevntion is to provide an'improved tool of the foregoing character which" is capable'oi honing bores as smallas rs with a .high degree of accuracy, which tool is of simple construction,` is quite'rugged, and is comparatively inexpensive.' f-

Another object/is to provide improved abrasive supporting and expanding means for small' bore hones whereby smallbores may be honed quickly and accurately-` f A further object is to provide a small bore hone including' a plurality voi `circumierentially#spaced 4abrasive carriers'which may he" expanded and contracted through a greater rangeofthan prior tools-of this character. f

' additional object is to 'provide a tool of the foregoing character wherein the abrasive carriers are `supported'in a rigid solidbody throughout their entire range of adjustment.1 il

A more specic Objectis to provide a tool of the foregoing character' having a 'plurality of abrasiveV carriers supported for expansion-and movement contractionA movements,`withf the innerlendsof such carriers disposed in staggered, overlapping rela-tion in their fully- 'contracted condition whereby eritentof contraction is increased. 'A stillmore' specific object-iste provide a tool of theforegoing"character having a'. solid body 'with eiroumferentially-spaced,'if parallel-sided grooves" therein for -slidably receiving abrasive carriers, 'said gi'ooves'having their inner endscut away diagonally so that they may project inwardly in overlapping relation. with respect' toeach other without intersection, which grooves have their deeper sides disposed forwardly of the tool radius with. respect to rotation to receive complementallyshaped abrasive carriers.

` 'Another object isto provide a tool ci the ioregoing clra'racter wherein 'an expanderelementds located in eachcarrier-receiving groove "atthe deeper side thereof, eachV which'expander element and 'carl-ier constitute a unitsubstantially -iilling j the groove in the contracted condition of the tool thereby providing compactnessiwith a greater range of expansion. f' 4Still another object is to provide improved means for adjusting a tool of the foregoing( charactor, and particularly adjusting means adapted to be actuated by manual orother power means as the -vhoning:operationprogresses, such, for ex# ample, as employed in varioustypes vof honing machines. f A further object is to provide carrier adjustment 'mea-ns fora toolof the'foregoing character `andwherein the adjusting pressure is applied through spring'means `setto giveway and relieve excessive expanding pressurelwhenra" predetermined expanding pressure is applied; thereby preventing -the Y' application of excessive abrading plessureto the work l l Other objects' are to provide an improved oarrier mounting whereby the carrier is retainedand contracted in an improvedvmanner conducive .to :f1-small size tool; to. provide forlongertoollife in a small bore device of the foregoing.V charactor; to provide a devicewhich may be contractedito a veryfsniall-diameter andexpanded toa vcomparai'lively large'diameter 'for honing alarga range' of sizes of small:bores.;` to providefor long:- er Aabrasive life in a tool of the foregoingvcharacter Withfaster honing operation; and to provide a` tool ofthe foregoing'character which ymayer:- curately beradjusted forY honing with precision. -1'Other objects and` advantages will become apparent` from-the following.descriptiony taken in conjunction with the appended drawings wherein, vFigure 1 is a side elevational view of one form of push-type 'hone embodying-my invention;` l Fig. 2 isia-n' enlarged, longitudinal, vertical sectional viewofa-portion of the hone-shown. in

f 1 Fig. 3 is a transverse sectional. view taken along the line 3--3 of Fig.-2; q

- Figd is a transverse sectional view taken along theline lli-4 offfliligl;l Figi-5 is anenlarged, cross-sectional view taken along the line. Ei--ofl'ig2;-v t n v l` Eig.- 6 i-sa top plan vie-w of a stone-carrier-unit for theihonefshown inFig. l; l Figi' '7`r lean-'elevational view of the ofthe honeshown in Fig.:.1;f'

Figfis a side elevational view of another form oi"pu'shtype lione embodying my invention;v 'f Fig.' 9 is anfrenlarged,- longitudinalfzsectional View of the fi'ontlportion fof the hone shown in Figi;V 'M 1.25 l Fig. 10 is an enlarged, longitudinal, vertical sectional view of 'the-.rear portionfottherhone shownin Figrl 'w :t l; Fig 1l f-is '1 an enlarged, cross-sectional view taken alongthe line l l-| I of Fig: 9;

front end Fig. 12 is an enlarged, cross-sectional view taken along the line |2|2 of Fig. 9;

Fig. 13 is an enlarged, cross-sectional View taken along the line 3-I 3 of Fig. 9;

Fig. 14 is a side elevational view of a retainer spring for one of the stone-carrier-units for the hone shown in Fig. 8;

Fig. 15 is a top plan view of a stone-carrierunit for the hone shown in Fig. 8;

Fig. 16 is a side elevational view of a pulltype hone embodying my invention;

Fig. 17 is a longitudinal, vertical sectional view of the hone shown in Fig. 16;

Fig. 18 is a top plan View of a stone-carrierunit for the hone shown in Fig. 16;

f wardlyY of the channel against the guide slot bot- Fig. 19 is a cross-sectional View taken along the line |9-i9 of Fig. 17;

Fig. 20 is a cross-sectional View taken along the line 20-20 of Fig. 17;

Fig. 21 is' a cross-sectional view taken along the line 2 |-2| of Fig. 17; and

Fig. 22 is a cross-sectional View taken along the line 22-22 of Fig. 1'7.

Referring to the drawings, the push-type honeillustrated in Fig. l is provided with an adapter head 25 adapted to be supported in a machine, for example a honing machine (not shown), for rotatively driving the tool. A tubular drive shank 26 is rigidly secured to the adapter head 25 in axial alignment therewith and slidably supports an external centering cone 21 for movement therealong. The outer end of the drive shank 26 has an internal thread 28 (Fig. 2) which threadedly receives one end 29a of a body member 29, the other end of which has a reduced portion 30 on which is secured a circular end-plate 3|. Y

The body member 29 serves as a support for the abrading means. drical shape and, preferably, is formed from metal for maximum strength and rigidity. Specifically, body member 29 has three longitudinally disposed channel-like guide slots 32 (Fig. 5) equally and circumferentially spaced in the body member with oppositely disposed side walls 33 and 34 of each guide slot 32 being ranged parallel to 'and equally spaced on opposite sides of an axial plane passed through the body member. An important feature of my invention resides in the specific arrangement of the side walls 33, 34 and a bottom wall 35 of each of the guide slots 32. In this respect, it will be noted (Fig. 5) that the side wall 33 has a greater depth internally of body member 29 than that of the side wall 34 and that these side walls are joined by the diagonally disposed bottom wall so that the inner ends of the slots 32 are in effect disposed in staggered overlapping relation. Each of the deeper side walls 33 is arranged in advance relation to or forwardly of the guide slot 32 when the tool is rotated in counterclockwise fashion (Fig. 5) about the axis of the body member 29 so that the least deep side wall 34 for each of the guide slots 32 constitutes the trailing wall of the guide slot when the tool is so rotated. This relative arrangement of the walls 33 and 34 is important for the greatest advantages offered by my invention, as will be more fully explained hereinafter. It will be understood that, if rotation of the hone `is in the opposite direction (clockwise, Fig. 5), the relative positions of the sides 33 and; 34 should be reversed to maintain the'deepest, side 33 in leading relation to the direction of rotation of the tool. The reasons for the relative arrangement of the sides 33, 34 and the bottom 35 of the guide tom 35 to allow maximum contraction of the carriers. f

An abrading element in the form of an abrasive stone 38 is secured to the top or outer edge of each carrier 36 to form in effect a substantially .It is generally of a cylinv integral stone-carrier-unit 40 which is retained in the slot 32 against axial displacement in one direction by the end plate 3| and in the other direction by a washer-like plate 4| disposed intermediate the end of the drive shank 26 and an abutment 42 (Fig. 2) formed by the reduced end portion 29a of the body member 29. The plate 4| has radially inwardly directed tongue portions 43 (Fig. 4) shaped and disposed to be freely received in the guide slots 32 and to substantially close each guide slot except for a notch portion 44, the purpose of which will be described hereinafter.

Spring means constantly tends to contract the stone-carrier-units 40 in the slots 32 and is adapted to hold them in contracted relation. This means includes a leaf spring 45 for each of the stone-carrier-units. The springs 45 are distributed circumferentially about the periphery of the body member 29 between each two adjacent stone-carrier-units 40 and each spring has one of its ends received in an opening 46 of rectangular shape in the end plate 3| to prevent angular displacement thereof. The other end of each spring 45 is received in an opening 4l of similar rectangular shape and located in the plate 4|, whereby the spring end received in the opening 4l is held against angular displacement. Body member 29 has longitudinal channels 48 (Fig. 5) disposed about its periphery to receive each spring 45 wherein the springs are retained by the plates 3| and 4| in a position radially inwardly of any arc that may be described by the abrasive surface of the stones 38 when the tool is rotated with the stones in their contracted position. Further, the body member 29 is cut away circumferentially to form an annular channel portion 49 (Figs. 2 and 5) in communication with each of the guide slots 32 to allow an arm 5|, which is integral with and formed transversely and inwardly from each spring 45, to project into the guide slots 32. The projecting end 5| of the spring 45 is received in a notch portion 52 disposed in the side of the carrier element 36 wherein it rests upon the carrier element and yieldably retains the stone-carrier-units 40 in contracted position in the body member 29. When the st0ne-car rier-units 40 are radially expanded by means later to be described, the projecting ends 5| cause the springs 45 to be angularly displaced and to continuously urge the stone-carrier-units to their contracted position in opposition to the yforces exerted by the expanding means.

Expanding means of the so-called push-type is provided for each of the expansible stonecarrir-un'S 40. It includes a push rod 53 (Fig.

l) which is slidably supported within the drive shank 2t and is removably retained therein by an annular, split spring-ring 54. disposed in fric--v tional engagement with the internal side walls of the drive shank Z5. The outer end of the push rod 53 has a pressure button 55, secured thereto and adapted to be engaged by the driving and operating mechanism (not shown) for the tool to advance the push rod internally of the drive shanlr 2li and to cause an inner end 5t (Fig. 2) of the push rod to move axially out-- wardly of an enlarged bore portion 5? in the drive shank. A generally cylindricallyshaped element 53 (Fie. 2) is slidably supported .in the enlarged bore portion 5l' and normally has its one end 5! held in Contact with the end 56 or the push rod by a compression spring 6,0 having one of its ends received in. an axially disposed opening Eil in the element 53 and its other end engaged with the inner end 29a of the body member 29. Axial alignment of the spring with the body member 2e is maintained by a pilot element 2do integral with the body inember 2e and projecting inwardly of the spring. The compression spring @El not only urges the element 5B into contact with the push rod 53 but also provides the means for restoring the push rod inwardly when pressure is removed iro-m the pressure button 55 so that the tool conf tractive means above described may be effective to contract the tool.

actuating means is provided to supply an operative connection between cylindrically-shaped element l and the expansible stone-carrierunits di?, whereby when the ele nent 5d is moved axially outward or forward in the bore portion el' by the push rod 53, the stone-carrier-units will be expanded radially of the body member 29. This actuating means comprises an `,actuator blade operatively associated with each of the stone-carrierunits 423 and disposed each guide slot 32 for longitudinal sliding movement thereof along the advance side walls 53. It will be recalled that the plate 4i (Fig. li) was described as having a notch portion @it in each of the tongues These portions i4 `are so proportioned as to allowthe actuator blades 52 to freely slide therethrough during the ac tuating movement oi the blades. Each :or the actuator blades iii extends axially inwardly oi' the bore portion di and along channel portions lift (Figs. 2 and 3) disposed longitudinally of the element 553 to a circumferential i s,posed groove in the element where thd` terminate in hook-like ends @2i serving to loclr Athe actuator blades to the element for movement therewith.

The outer or forward end portion of each actuator blade has `two cani portions i and el disposed `with their cam yedges parallel relation on the blade. These cani portions re Spectively underlie `comiden-lentaryfshaped cam `portions @il and Si? formed in the stone ycarrier 36 on the side thereof disposed along-vtheadvance side wall of the guide slots 32, ln other words, the inner forward (with respect to tdi,- rection of rotation) edge portionoi" keach carrier .35 is provided with a rectangularly shaped notch adapted to receive the expander blade the upper wall of the notch being lshaped complementally to the cams and ill of such blade to provide the cam portions .et and fi referred to. In `this way vthe carrier 36 and blade 5 2 v substantially completely vfill the `slot 32 with the partsfree to slide as described, namely, the car kso rier radially and the blade longitudinally. It follows, that any force tending to angularly displace the stone carrier element 36 in a clockwise direction (Fig. 5) will cause the radially innermost portion of the stone carrier element to press the actuator blade 62 against and along the innermost portion of the advance side wall 3 3. Further, the forces exerted on the respective side walls 3ft and 33 of the guide slots 32 will be distributed along aline 'Iii representing the line of contact of the upper or outer edge, of the stone carrier element 36 with the trailing side wall 3c and a line il representing the line of Contact of the lower or innermost edge of the carrier element along the actuator blade 62, whereby the actuator blade is pressed against the advance side wall 33. Attention is again directed to the relative depth with which the side Walls 33 and 34 penetrate inwardly' of the body member 2Q and by means of which the inclined bottom surface 35 of the guide slot 32 is provided. By allowing the advance side wall 33 to penetrate the body member a maximum distance inwardly, the lines lll and li will be spaced a maximum distance apart. Further, by having the trailing side wall 364 penetrate interiorly of the body member 2e a lesser extent, not only is less material of the body member 29 cut away to form the guide slots but more space is provided in the body members for allowing the advance side walls 33 of the other guide slots in the tool to penetrate further inwardly of the body member. A most important feature of the described arrangement of the side walls of the guide slots 32 is the maximum spacing obtained between the Ydescribed pressure application lines Alil and ll, in a radial direction along axial planes disposed centrally of the slots. It has been iound that the greater the spacing between the `lines vlil and ll in the direction mentioned, the more rigid and stable support the stone-carrier-units (iii will have during a honing operation. Any slight rocking or angular `displaceinent oi the units due to the rubbing action of the stones on the cylinder wall being honed will be in a clockwise direction (Fig. 5), establishing a pivot axis coinci ing with the line li?, and the edge coinciding with the line 'H will constitute the swinging edge. If any space exists `between the unit and :the side Wall 33 of `the slot, the edge represented by the line TH will be checked in its movement `by the side wall 33 (acting through the blade With less angular movement of the unit would occur in the case of any .portion of the unit removed radially outwardly from the line ll. Therefore the greater the extent the edge represented `by the line li is disposed radially yinwardly from the outer edge ci `the slot, the greater will be ytlie stability of the una yin the not. renner, the ,buey ,member is stronger and v:the tooican be made with a smaller -diameter to accor eclate small bores :and at the same tinewill Vh ve van increased expansive range with greater rigid ty throughout its range or" expansion.

`When using my Ytool for honing small bores,

Ithe A'tool is connected with suitable machine,

for example a honing machine (not shown) h v- `ing rotatable drive means and Ioperating `means for lthe tool. The vusual controls'associated with .the Vvhoning machine .are .operated to rotatably drive lthe tool and to `engage the pressure ybutton $5 `and move the push rod v53,outwardly `the drive :shank 2li. Movement of the push rod l53 lcauses `the element lid t0 mOVc outwardlyin the bore il? asa resultof the direct Vcontain; .of

the end 56 of the push rod with the end 59 of the element 58. The outwardly directed movement of the element 58 not only compresses the compression spring 60 but also moves each actuaior blade 62 axially outwardly whereby the cam portions 66 and 81 on the actuator blades cooperate with the respective cam portions G8 and 59 on the stone carrier element 36 to move each of the stone-carrier-units 40 radially outwardly, while maintaining the relative parallel alignment of the abrading surface of each stone 38 with the axis of the body member 29. The work piece (not shown) containing the bore that is to be honed may be engaged with the hone in contracted condition and the stone-carrier-units 49 are then expanded in the manner just described to contact the surface of the bore and perform the required honing operation while the hone is being rotatably driven.

During the honing operation the tool shown is rotated in a counterclockwise direction (Fig. and the abrasive action of the stones 38 on the wall of the bore will tend to angularly displace each of the stone-carrier-units 49 in a clockwise direction (Fig. 5); but due to the particular arrangement described and the relative proportions of the walls forming the guide slots 32, particularly by having the advance wall 33 extending inwardly of the body member a maximum distance, this tendency towards clockwise displacement is most eifectively counteracted to provide maximum rigidity for the stone and carrier assembly.

Assuming that the bore has been completed to the desired size and with the required surface finish, the appropriate controls associated with the honing machine are operated to release the pressure that was previously applied on the pressure button 55. Then, the energy stored in the compression spring 60 causes the element 58 to be moved axially inwardly of the bore 51 and to draw the actuator blades 52 therewith. Further, the movement of the element 58 restores the push rod 53 to its original and normal position. When the actuator blades 62 are moved axially inwardly, the contraction leaf springs 45 cause the stone-carrier-units 40 to move inwardly of their respective supporting guide slots 32 to their contracted position. Likewise, should the actuator blades 62 be partially moved inwardly by partial restoration of the pressure button 55 and the element 58, the leaf springs 45 will cause the stone-carrier-units 49 i'o be retracted an extent as determined by the relative positions of their cam portions 68 and 69 with the respective cam portions 65 and 61 on the actuator blades 62.

The modified vform of push-type hone embodying my invention shown in Figs. 8 to 15, inclusive, will now be described. With reference to the hone illustrated in Fig. 8, the tool includes expansible abrasive means and other elements which are similar in construction to certain of the previously described elements found in the push-type hone illustrated in Figs. 1 to 7, inclusive. For this reason, like elements in the two tools will be identified by the same reference numerals, except in so far as their respective portions diier one from the other. Specifically, the hone illustrated in Fig. 8 has a push rod 53 (Fig. 10) which is slidably supported in the drive shank 26 and is limited in its sliding movement therein by a pin secured in the side wall of the drive shank with its one end received in an elongated notch portion 16 disposed in one side of the push rod. A second push rod 11 (Figs. 9 and 10) is located in the drive shank 26 and. has one of its ends received for limited sliding movement in an axial bore 18a disposed in the inner end of the push rod 53. The limited sliding movement of the second push rod 11 in the bore 18a. is controlled by a pin 19 supported by the push rod 53 and having its free end disposed in a notch portion 88 located in one side of the second push rod 11.

The other end of the push rod 11 has an enlarged head portion 18 (Fig. 9) which projects into the bore 51 and provides an abutment for one end of a pre-loaded compression spring 8| which surrounds the push rod 11. The other end of the spring 8| limits against the inner end of the push rod 53 to hold push rod 11 in outwardly extended and yieldable relation with the push rod v53 to an extent determined by the contact of the pin 19 with the end wall 80a of the notch portion 88. This construction is such that upon movement of the push rod 53 axially outwardly or forwardly of the drive shank 26, the push rod 11 will be carried therewith unless or until the head 18 meets with sufficient resistance to overcome the expansive force of the spring 8|, in which event the movement of push rod 53 will be relative to the push rod 1l' until the pin 19 contacts the opposite side wall h of the notch portion 80.

An operative connecting means is provided between the push rod head 18 and the actuator blades 62, which includes a generally cylindrically-shaped element 82 (Fig. 9) in which is located an axially disposed bore 83, one end of which is closed by a plug element 84 secured in the bore 83 by any suitable fastening means, for example a pin 85. A circumferentially disposed groove 86 is located in close proximity to the other end 81 of the element 82 for receiving the hook-like end portions 65 of the actuator blades 62 for locking these hooked end portions to the element 82. The actuator blades 62 are freely received for movement along channel portions 83 disposed in the end 81 of the element 82. An axially disposed opening 89 is located in the outer end of the element 82 in communication with the bore 83 for freely receiving a push pin 90 which projects outwardly of the element 82 from a circular head portion 9| which is integral therewith. The head portion 9| serves as a seat for one end of a compression spring 92 located in the bore 83, the other end of which is limited against the inner end of the plug element 84. When the tool is at rest and in fully contracted condition, the arrangement and structural characteristics of the parts previously described is such that the outer end of the push pin 90 is held in contact with the inner end 29a of the body member 29 and the wall 16a (Fig. 10) of the notch portion 16 is held in contact with the pin 15 by the pre-loaded condition of the compression spring 8| and the spring 92. It should be mentioned at this time that the spring 8| requires a greater force to effect its further compression than the force required to effect compression of the spring 92. Thus, it can be seen that when the push rod 53 moves inwardly of the drive shank 28 transmission of its movement will be through the spring 8|, and the spring 92 will be compressed as a result of the relative compressibility factors of the two springs. This arrangement, including the relative compressibility factors of the two springs 8| and 92, limits the expansive pressure applied lotyfrimber et au times. Each ofthe cone-ue 'portions |22 hasa transverse notchportioh |23 (lFigs. 17 and 21) in which is received and locked ltherein a hook-like end 24 on each 'actuator The expansible abrasive means later described 'isexpanded as a result of movement of the actu- ;ator bladesv |2|. However, in the pull-type of line, movement of the actuator blades |2| axially inwardly of the body member ||3 is used to exfpand'sthe abrasive lmeans, whereas in the previously described fpush-type hone expansion was Each of ahdtZG which are adapted to cooperate respec- 4tively 'with a pair of cam portions |21 and |28 forming a part of a stone carrier |29 which carrier is similar in all respects to the previously described stone carrier elements 36 and 93, except for a reversal in arrangement of its cam` portions |21 and |28. Likewise, the stone-carrier-unit |30 is similar in all respects to the stone-carrierunit (Fig. 6) except for the previously described reversal of the cam portions |21 and |28.

In the use of the pull-type hone, the tool is placed in registration with the bore (not shown) to be honed and the adjusting nut ||1 is rotated in a clockwise direction (Fig. 22) to threadedly draw the actuator cage |20 inwardly of the adjusting nut I1 and its tongue portions |22 longitudinally of the channel portions |3f in the body member ||3. rlhe actuator blades |2| are drawn axially inwardly by means of their hook-like end portion |26 being locked in the notches |23 of the actuator cage |20 to cause the cam portions |25 and |26 on the actuator blades to cam the bladecarrier-units |30 radially outwardly and into contact with the wall of the bore to be honed. Thereafter, with the units remaining in contact with the wall, continued clockwise adjustment of the adjusting nut ||1 (Fig. 22) causes the nut to advance along the threads on the actuator cage |20 and axially outwardly of the body member ||3, until an end ||1a of the 4adjusting nut ||1 contacts the jam-nut ||4', to compress and load the compression spring whereby the abrasive stones |3| are held in contact with the wall of the bore to be honed with a pressure in accordance with the loaded condition of the compression spring |8. During a following honing operation and as the wall of the bore is abraded away, the stone-carrier-units |30 automatically expand radially outwardly to remain in contact with the surface of the bore being honed because of the compressed condition of the spring ||8. This movement of the stone-carrier-units |30 in an outward direction is caused by the actuator blades |2| moving axially inwardly of the body member I3 which in turn results in the adjusting nut |1 moving axially inwardly along the reduced portion l |3d of the body member until the adjusting nut contacts the connection ||2 to arrest further expansion and abrading action of the stones |3| on the wall of the bore being honed. When it is desired to contract the stone-carrierunits |30, the adjusting nut ||1 is adjusted in a counterclockwise direction (Fig. 22) to move the actuator cage axially outwardly of the body member 3 which in turn moves the actuator blades |2| outwardly so that the springs |32 are allowed to move the stone-carrier-units radially inwardly of the body member |3 and to their desired contracted position.

The structure embodied in mv described honesA auows apirality of stone-'earff-uriirs'to'be'used in a small bore hone with increased support for the carrier units and greater rigidity of the tool. By cutting the guide slots in the body member of the tool with an inclined bottom wall and by forming the inner end of the stone-carrier-unit complementary therewith, I have not only in creased the expansible range of the tool but, also, have provided greater rigidity throughout the range of expansion by having the greatest point of depth of the bottom wall of the guide slot forwardly of the direction of rotation of the tool. Further, my yieldable retaining springs for each of the stone-carrier-units are easily removable from their retaining position on the carrier unit to allow a worn unit to be readily replaced without dismantling the hone.

I claim:

1. A honing tool adapted to be rotated in a predetermined direction comprising a body member having a plurality of circumferentially spaced closed-bottom slots each of which is intersected by the tool radius along a line parallel with the slot sides, said slots having similarly arranged generally diagonally disposed bottom walls extending inwardly and forwardly from one side wall thereof with respect to direction of rotation of the tool, abrasive carriers mounted for expansion and contraction in and shaped complementally to said slots, and a separate carrier expanding cam member mounted in each of said slots between and in operative engagement with the carrier and the slot bottom and adjustable longitudinally therein in one direction to expand said carrier and in the opposite direction to permit it to contract.

2. A honing tool adapted to be rotated in a. predetermined direction comprising a body member having a plurality of circumferentially spaced, longitudinally-extending closed-bottom slots each of which is intersected by the tool radius along a line parallel with the slot sides, said slots having similarly arranged generally diagonally disposed bottom walls extending inwardly and forwardly from one side wall thereof with respect to direction of rotation of the tool, elongate abrasive carriers mounted for expansion and contraction in, shaped complementally to and substantially lling said slots, a separate carrier expanding blade mounted in and slidable longitudinally of each lof said slots between the bottom thereof and the carrier, and expander elements on said carriers and blades having inclined surfaces complemental to each other whereby longitudinal adjustment of each said blade in one direction expands the respectively engaged carrier and adjustment in the opDOsite direction permits contraction of the respectively engaged carrier.

3. A honing tool adapted to be rotated in a predetermined direction comprising a body member having a plurality of circumferentially spaced closed-bottom slots each of which is intersected by the tool radius along a line parallel with the slot sides, said slots having similarly arranged generally diagonally disposed bottom walls extending inwardly and forwardly from one side wall of each said slot past said tool radius with respect to direction of rotation of the tool, abrasive carriers mounted for expansion and contraction in and shaped complementally to said slots, the forward edge of each said carrier having a rectangularly shaped notch, expanding cam elements on one wall of each said notch and an elongate carrier expanding Y Y 13 bladeV mountedk in each of said slots within said carrier notchand ,bearing against said bottom wall and having expanding cam 'elements complemental to and engageablev with the iirlst mentioned camv elements, the 'arrangement of the Vcam elements being such that simultaneous adjustment yof yall said blades rin one direction simultaneously expands all said carriers. 4. A head for a small bore hone, adapted to be rotated in a predetermined direction comprising a body member having ak plurality of longitudinally-extending circumferentially spaced closed-bottom slots, each 'of which is intersected by 'the fhead 'radius along a fline parallel with the slot sides, said slots having similarly arranged generally rvdiagonally disposed bottom wall'sex'tending inwardly and forwardly from one .side wall fofv each "said 'slot beyond saidY head radius with 'respect to direction of y rotation of the head, and 'a carrier-expander unit mounted in each of said "slotsffor expansion and contraction therein, shaped complementallythereto Land substantially filling it, each said unit including a carrier having lside and bottom Walls shapedsimilarlytothe corresponding'slot `wal1s except for a'rectangularly-shaped notch'in the inner'ioi'w'ard partof the longer or 4leading unit Yside. wall, yan expander blade snugly and slidably fitted in each said ynotch and'seated against thebottorn wall of lthe slot to'complete the complemental shapeofthe unit with lrespect to the slot,l and complemental engaged expander elements "on each said carrier `and blade within the coniinesofl said unit 'and `adapted to expand saidicarrier as said blade is moved longitudinally in .one direction.l

t V5. A small'bore'honing vtool ofthe character described adapted to be rotated'in a predetermined direction, which comprises 'a cylin-4 drical body member having ak longitudinallyextending closed-bottom\ slot with .parallel "side walls and intersected inparallel relation to said side walls by the tool radius, .the oneof said sidewalls located forwardly of thetool radius,

with respect to direction of `rotation of theftool,

being substantially deeper than Vthe j other "or 4trailing side wall provid'i'ng a slot bottom wall inclined throughout its major portion inwardly and forwardly with respect to direction `of rov ,tationand having a portion normal to said one side wall, said slot extending radially Ainwardly to an extent lwhereby themid-point of said bottom ywallijs short of the center of the body, an abrasive carrier shaped 'substantiallyfcomplementally to and snugly. slidable in `expanding and contracting directions withinl said slot and having a notch lat the lower edge of said deeper side wall equal in width to said` normally .extending bottom wall portion, a vthin carrierY .expander blade mounted in and s'lidable longitudinally of said slot withinthe boundary of the wallsof said slot in bearing relation between fsaid slot bottomand said carrier, and inclined ccmplemental expander cam surfaces on each l 6. Ahoning tool of thebharacter described adapted to be4 rotated in a predetermined direction. whichA comprisesa body vmemberprovided with a pluralityI of Vcireumierentially-spaced; lon- Which isintersectd by a tool radius, the 'side' 'Walls gitudinally-extending closed-bottomslots each of 14 of 'eachsaid slotw being parallel/ with the radius line ofthe respective slot with the :side wall disposed Jforwardlyy with lrespect 'to the direction of rotation extending 'inwardly a greater distance than the otherjside wall, each 'said slot having a bottom Wall surface inclined inwardly'and forwardly from the shallowerside wall to a point forward of the intersecting ,radius line, so thatthe bottom walls of all said slots are disposed in staggered, overlapping relation to i avoid yinterference with each other, abrasive -carriers mounted in said slots respectively, and carrier expanding cam "elements mounted within said `slots respectively'inbearing relation tothe Vcarrier and vthe slot bottom and movable longitudinally thereof to expand andenablec'ontraction oi vsaid carriers, said expanding elements ,being disposed in nested relation tosaid carriers respectively so that said carrier and'expandingelements'in contractedcondition are ofsubstantially the cross"- se'ctionai shape of saidislots which are l lled thereby," `said`expanding elements'having portions adapted for connection with actuating means for moving the lexpanding 'elements longitudinally. 7. A line'adapted'to be rotated'in a'predetermined direction including abody member'having a plurality4 of longitudinally extending radial guide slots disposed therein, saidjguide'slotsv Veach having 'a longitudinal'side wall disposedl parallel with and" on 'each of the" oprxjsiteA sides of 'an axial plane passed throughsai'd'body member,V oneof said longitudinal sidewalls of each of said guide rslots being disposed inadvance relationin respect tothe direction of rotationfvoisaidl hone and extending inwardly ofsaid'body member a greater extent than they other saidlongitudinal "side wall, each slot thereby having a relatively deep Side anda relatively shallowside and the bottom walls of said` slots being thereby inclined and in ystaggered, overlapping relation, "ajstone-carrier-unit disposed in each of s'aidguide slots for radial movement thereiniand having la bottom surface inclined'generally complementallyto the bottom wall of the ,slot, anexpander element'located substantially within each of said' guideslotsadjacent'the deeper side thereof vand operatively connected to ysaid stone-carrier-unit to radially 'expand said unit, and aseparate torsion' spring for each 'ofsaid vunits'supported on saidfbody member andhaving atleasta portion engaging they corresponding'runit to vurge saidj unit radially inwardly oi said body member and said'guide slot.

'8. Structure of the class described for honing small bores which comprises a headmember having an enlarged body portion witha reduced axial extension, said head member having a plurality of circ'umferentially` spaced slots extending ,throughout said `enlarged body portion and extension, abrasive carriers mounted insaid slots within said body portion, end plates at the Yopposite ends of said body portion for retaining said abrasive carrierslongitudinally therein, the inner koi said end plates having openings aligned ywith said slots, an expander blade mounted in each of said slots and including 'an expanderV part disposed in the vslot of said body'portion and an actuating partv projecting therefrom through the respective opening in said `inner end plate, a hollow 'drive shank connected to said reduced head portion, confining said inner end plate and enclosing the actuatingvpart lof said expander blade,

fmeans inlsaiddrve' shank connected vwith lthe ractuating vparts offsaidfblades thereinV and 'adjuffstable` longitudinally .offsaid drive `shank for -simultaneously nio'vmg all saidblades to expand lsaid abrasive carriers, and rst spring means in said drive shank adapted to be compressed as said expanding means is moved in expanding direction and tending constantly to move said expanding means in the opposite direction to permit contraction of the tool, and second spring means connected to said head and engaged with each of said abrasive carriers for moving them in contracting direction when said rst spring means is eiective to move said expanding means in contracting direction.

9. A small bore honing tool comprising a body member having an abrasive supporting portion and a reduced drive extension, a plurality of circumferentially-spaced slots in said body member extending longitudinally throughout said abrasive supporting portion and said extension, abrasive carriers mounted in said slots, end plates at the opposite ends of the supporting portion of said body member for conning said abrasive carriers against longitudinal displacement, the inner of said plates having openings aligned with said slots, an expander blade in each of said slots having an enlarged head part located between said end plates and adapted to expandingly engage said abrasive carrier, and a reduced stem part projecting through and beyond the respective plate opening, a hollow drive shaft secured to said reduced extension and housing the stem portions of said blades, a longitudinally adjustable member in said shaft connected to all said blade stems for simultaneous expansion and contraction movement thereof, a spring in said drive shaft yieldably opposing expansion movement of said adjustable member and adapted to move said adjustable member and blades in contracting direction when said adjustable member is released for that purpose, and spring means connected to said head and engaged with each said abrasive carrier for contracting it when said first spring is effective to contract the tool.

10. A tool of the class described which comprises a honing head, abrasive carriers carried by said head for expansion and contraction movements, means carried by said head for expanding said carriers, means carried by said head for contracting said carriers, a hollow drive shaft for said head, and means for actuating said expanding means including a longitudinally-adjustable member in said drive shaft, a second longitudinally-adjustable member in said drive shaft, a pre-loading spring interengaging-and reacting between said first and second members and by which movement of said first member is imparted to said second member, a third longitudinally-adjustable member in said drive shaft connected to said expanding means and actuated by said second member, said pre-loaded spring being adapted to yield and relieve pressure applied through said iirst and second members when a predetermined pressure is exceeded, and a second spring interengaging and reacting between said third member and a relatively fixed portion of said tool and adapted to be compressed by said third member when it is moved -to expand said carriers so as to move said iirst, second and third members in return direction from expanding position when expansive pressure is released therefrom to enable contraction of said carriers.

1l. A rotatable tool of the class described which comprises a honing head, abrasive carriers carried by said head for expansion and contraction movements, means carried by said head for expanding said carriers, means carried by said head for contracting said carriers, a hollow drive shaft for said head, and means for actuating said expanding means including a pair of longitudinally reciprocable members mounted in said drive shaft, iirst spring means interposed between said expanding means and a relatively fixed portion of the tool and reacting in axial di rection for biasing the expanding means in retracting direction, one of said reciprocable members being operator-controlled during rotation of the tool, and a second, pre-loaded spring interconnecting said reciprocable members so that longitudinal movement of one is transmitted to the other through said spring, said second spring requiring a greater force for compression thereof than the first spring means, said second spring being set to give way at a predetermined pressure to relieve against the application of more than a predetermined expansive pressure,

12. A tool of the class described which comprises a honing head, abrasive carriers carried by said head for expansion and contraction movements, means carried by said head for expanding said carriers, means carried by said head for contracting said carriers, a hollow.drive shaft supporting said head, and means for actuating said expanding means including a pair of longitudinally adjustable members mounted in said drive shaft, one of which members is operatively connected to said expanding means, a preloaded spring interposed between said members so that longitudinal movement of one is transmitted to the other through said spring, said spring being set to give way at a predetermined pressure to relieve against the application of more than a predetermined expansive pressure and a second spring inter-posed between one of said adjustable members and a relatively iixed portion of said tool and adapted to be loaded by movement of said adjustable members to expand said carriers in readiness to move said adjustable members in return direction from expanding position upon release of expanding pressure.

13. A tool of the class described which comprises a honing head, abrasive carriers carried by said head for expansion and contraction movements, means carried by said head for expanding said carriers, means carried by said head for contracting said carriers, a hollow drive shaft supporting said head, and means for actuating said expanding means including a first and a second longitudinally adjustable member mounted in said drive shaft, the second member being operatively connected to said expanding means, a pre-loaded spring interconnecting said members so that longitudinal movement of one is transmitted to the other through said spring, said spring being set to give way at a predetermined pressure to relieve against the application of more than a predetermined expansive pressure, means including interengageable stop elements on sad first member and said drive shaft for limiting the extent of longitudinal movement of the member relative to the drive shaft for limiting the range of tool expansion, and means including a lost motion connection between said mebers for limiting movement of said members relative to each other when said predetermined pressure of said pre-loaded spring is exceeded.

14. A tool of the class described which comprises a honing head, abrasive carriers mounted in said head for expansive and contractive movements, longitudinally movable means mounted in said head for expanding said carriers, means mounted in said head for contracting said carriers, a hollow drive shaft connected to said honing head, and means for actuating said expanding means including a member mounted within said drive shaft for longitudinal reciprocation relative thereto and rotative movement therewith, said actuating means beingconnnected with said expanding means and operative for moving the latter longitudinally, said member having a central axial opening therein, a spring mounted in said axial opening and operatively connected to said honing head and reacting between said honing head and said member, whereby said spring is compressed as said member is moved longitudinally relative te said drive shaft toward said head and is conditioned to move said member and expanding means in return direction from expanding position when expanding pressure is removed from said member.

15. A tool of the class described which comprises a honing head, abrasive carriers mounted in said head for expansive and contractive move ments, means mounted in said head for expanding said carriers, means mounted in said head for contracting said carriers, a hollow drive shaft connected to said honing head, and means for actuating said expanding means including a member mounted within said drive shaft for longitudinal movement relative thereto and rotative movement therewith and connected with said expanding means, said member being hollow with its opposite ends substantially closed, a spring mounted within said member, a spring actuator mounted in said member in engagement with the end of said spring adjacent said honing head, said actuator having a part extending through the adjacent end of said member into engagef ment with said head, whereby said actuator compresses said spring as said member moves in expanding direction to condition said spring to move said member in contracting direction when expanding pressure is removed therefrom.

16. In a honing tool of the type having a hollow drive shaft, a honing head carried by said drive shaft, abrasive-carriers carried by said head for expansion and contraction movements,

18 and means for expanding and contracting said carriers including an actuating member slidable longitudinally in said head, the improvement which comprises a longitudinally slidable thrust member in said shaft having effective engagement with said actuating member and operative for transmitting thrust to the latter, a longitudinally slidable push member in said shaft, a preloaded spring engaging and reacting between said push member and thrust member normally operative for transmitting thrust between the members, said push member and thrust member hav ing lost motion connection enabling relative motion therebetween upon yielding of said preloaded spring, said .push member and shaft having interengageable stop elements for limiting the extent of longitudinal movement of the push member relative to the shaft, and means constantly biasing the thrust member and push member longitudinally in the direction away from said head. HENRY ROBERT BILLETER.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,696,477 Hall Dec. 25, 1928 1,796,060 Summers Mar, 10, 1931 1,832,635 Johnson (Nov, 17, 1931 1,850,847 OBrien Mar. 22, 1932 1,978,712 Kern Oct. 30, 1934 1,989,831 Sunnen Feb. 5, 1935 2,053,977 Taylor Sept. 8, 1936 2,102,053 Batzer Dec. 14, 1937 2,195,061 Wallace Mar. 26, 1940 2,331,523 Wacker Oct. 12, 1943 2,343,013 Kline Feb. 29, 1944 2,376,851 Sunnen May 22, 1945 2,483,997 Gjertsen Oct, 4, 1949 FOREIGN PATENTS Number Country Date 416,571 Great Britain Sept. 18, 1934 595,280 Germany Apr. 9, 1934 

